General and Efficient Transesterification ofβ-Keto Esters with Various Alcohols Using Et3N as a Brønsted Base Additive
摘要:
Transesterification of beta-keto esters with a wide variety of allyl, benzyl, propargyl, and alkyl alcohols using, for the first time, commercially available and inexpensive Et3N as a Bronsted base additive, is efficiently performed in toluene at reflux. The corresponding esters are exclusively obtained in 57-98% yields with no trace amounts of gamma,delta-ketones, usually expected from the decarboxylative Carroll rearrangement.
α-EWG-Substituted Enones: Suitable Substrates for Ring-Closing Metathesis
作者:Julie Toueg、Joëlle Prunet
DOI:10.1055/s-2006-950274
日期:2006.10
The A-ring of hexacyclinic acid has been synthesised, using a ring-closing metathesis involving an α-EWG-substituted enone as the key step. We have then explored the scope of this reaction, which gives access to various 5- and 6-membered rings.
申请人:Korea Research Institute of Chemical Technology
公开号:EP0324626A1
公开(公告)日:1989-07-19
1,4-dihydropyridine derivatives represented by the formula:
wherein
R¹ and R², different from the other, is selected from the group consisting of lower alkyl, lower alkenyl, lower alkoxyalkyl or aminoaryl(lower)alkyl having carbon atoms of 1 to 6, which may be substituted or unsubstituted by a lower alkyl having carbon atoms of 1 to 4, wherein at least one of R¹ and R² is a lower alkenyl having carbon atoms of 3 to 6 whose 1- or 2- position is substituted by a lower alkyl having carbon atoms of 1 to 4; and
R³ is a nitro group in ortho-, meta- or para-position of the phenyl.
The compounds are useful as vasodilators and in the treatment of hypertension.